How to use variables within a JSON object with JustGage

I'm going crazy and hope someone can help. I have an array that I am accessing with Jquery using the getJson function.

I am trying to figure out how I can access and use the variables within the json object. I want to use the variables with a javascript plugin called justgage.

Here is my array on my_url.php

  <?php

$my_data=array(min=>"100",max=>"200", total=>"50");

// sending output
header('Content-Type: text/json');
echo json_encode($my_data,true);
?>

Here is my code that gets the array

<script>
$(document).ready(function(){
  $("button").click(function(){
$.getJSON("my_url.php",function(result){
 $.each(result, function(key, value){
                $("#showdata").append(key+value);
            });
        });
    });
});
</script>

Which gives me

min100max200total50

I want to know how to get this data into the variables needed by the justgage script below?

<script>

  var g = new JustGage({
    id: "gauge",
    value: total,
    min: 0,
    max: 100,
    title: "Sample Data"
  });
</script>

<script>
  $(document).ready(function(){
   $("button").click(function(){
     $.getJSON("my_url.php",function(result){
         var g = new JustGage({
          id: "gauge",
          value: result.total,
          min: result.min,
          max: result.max,
          title: "Sample Data"
       });
      });
    });
  });
</script>